Method, node, and system for notifying proxy update in WMN

ABSTRACT

Embodiments of the present invention disclose a method and node for notifying proxy update in a WMN and a WMN for notifying proxy update. By constructing the proxy update add message, where the proxy update add message includes the address of terminal, the current proxy node address after terminal switching and the destination node address of the terminal, and taking the address of the original proxy node before terminal switching as the address of the destination node, and sending the proxy update add message constructed to the original proxy node, where the proxy update add message is used for updating proxy information of the terminal in the proxy information table of the original proxy node to be the current proxy node address. It makes sure that packets received by the original proxy node which should be sent to the terminal could be received by the terminal, and packet loss rate during terminal switching could be reduced.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/CN2009/070710, filed on Mar. 10, 2009, which claims priority toChinese Patent Application No. 200810065571.8, filed on Mar. 14, 2008,both of which are hereby incorporated by reference in their entireties.

FIELD OF THE INVENTION

The present invention relates to communications field, and morespecifically, to a method, a Wireless Mesh Node, and a Wireless MeshNetwork (WMN) system for notifying proxy update.

BACKGROUND OF THE INVENTION

The proxy update mechanism of the WMN in the prior art makes it possiblethat when a node in the WMN needs to send a packet to a terminal, it maysend the packet to a proxy node of the terminal, namely the Mesh AccessPoint (MAP) associated with the terminal, and then the proxy nodeforwards the packet to the destination terminal. Before sending thepacket, the Mesh node first searches its own proxy information table,acquires the address of the MAP associated with the terminal, and thensends, according to the routing table, the packet to the MAP associatedwith the terminal. Thus, the routing table saved in a node of the Meshnetwork only needs to take the Mesh node as the destination addressrather than take the real destination terminal as the destinationaddress, and thus the size of the routing table is reducedsignificantly. If the terminal Station (STA) switches among differentMAPs, it becomes especially important to update proxy information in theMesh nodes to make sure that the terminal could still receive packetstimely and correctly.

According to the technical solution in the prior art, when the terminalSTA switches among different MAPs, the process is as follows:

First, STA1 accesses the network through MAP1, STA2 accesses the networkthrough MAP2, and STA1 and STA2 communicates with each other through theMesh network.

When STA1 switches from MAP1 to MAP3, STA1 establishes association withMAP3. At this time, MAP1 is the original proxy node of terminal STA1,and MAP3 is the current proxy node of STA1.

Then, MAP3 sends a proxy update add message to a proxy informationserver in the Mesh network, for example, taking Mesh Point Portal (MPP)as the proxy information server, where the proxy update add messagecarries a Proxy Update Information Element (PU IE), the MAC address ofterminal STA1, and the MAC address of STA1's current proxy node MAP3.

Through the proxy update add message, the MPP and nodes in the path fromMAP3 to the MPP are instructed to create or update proxy informationabout STA1.

After receiving the proxy update add message, the MPP node replies aproxy update confirmation message to MAP3, where the proxy updateconfirmation message carries a Proxy Update Confirmation InformationElement (PUC IE).

During research and implementation of the prior art, the inventor of thepresent invention finds the following problems in the prior art: Afterterminal STA1 switches, in the Mesh network, only nodes in the path fromthe current proxy node MAP3 of the terminal to the proxy informationserver MPP update the proxy information of the terminal timely, andother Mesh nodes that do not update the proxy information of theterminal timely would still send packets, which are intended to be sentto the terminal, to the original proxy node MAP1 of the terminal,resulting in packet loss.

SUMMARY OF THE INVENTION

The embodiments of the present invention provide a method for notifyingproxy update in the WMN, a WMN node for notifying proxy update in theWMN, and two types of WMNs for notifying proxy update. In this way,associated nodes can update proxy information timely when terminalswitches and packet loss rate during terminal switching is reduced.

The embodiments of the present invention provide a method for notifyingproxy update in the WMN, including:

constructing a proxy update add message, where: the proxy update addmessage includes the address of the terminal and the address of thecurrent proxy node after terminal switching, and the proxy update addmessage further includes the address of the destination node, where theaddress of the destination node is the address of the original proxynode before terminal switching; and

sending the proxy update add message to the original proxy node, namelythe proxy node before terminal switching, where the proxy update addmessage is used for updating the proxy information of the terminal in aproxy information table of the original proxy node to be the address ofthe current proxy node.

The embodiments of the present invention provide a WMN node fornotifying proxy update in the WMN, including:

a constructing unit, configured to construct a proxy update add message,where the proxy update add message takes the address of the originalproxy node of the terminal as the address of the destination node, andincludes the address of the terminal and the address of the currentproxy node of the terminal; and

a sending unit, configured to send the proxy update add message to thedestination node according to the address of the destination node in theconstructing unit, where the proxy update add message is used forupdating the proxy information of the terminal in a proxy informationtable of the destination node to be the address of the current proxynode of the terminal.

The embodiments of the present invention provide a WMN for notifyingproxy update, including: a current proxy node before a first terminalswitches, and an original proxy node after the first terminal switches.

The current proxy node includes:

a first receiving unit, configured to receive a request message sent bythe first terminal or the original proxy node, where the request messagecarries the address of the original proxy node;

a first resolution unit, configured to acquire the address of theoriginal proxy node of the first terminal from the request messagereceived by the first receiving unit;

a first constructing unit, configured to construct a proxy update addmessage according to the address of the original proxy node acquired bythe first resolution unit, where the proxy update add messageconstructed takes the address of the original proxy node as the addressof the destination node, and includes the address of the current proxynode and the address of the first terminal; and

a first sending unit, configured to send the proxy update add message tothe destination node according to the address of the destination node inthe first constructing unit, where the proxy update add message is usedfor updating proxy information of the first terminal in the proxyinformation table of the destination node to be the address of thecurrent proxy node, namely the address of the proxy node after the firstterminal switches.

The original proxy node includes:

a second receiving unit, configured to receive the proxy update addmessage sent by the current proxy node; and

a second proxy table unit, configured to update, according to theaddress of the current proxy node of the first terminal carried by theproxy update add message which is received by the second receiving unit,the proxy information of the first terminal in local proxy informationtable to be the address of the current proxy node.

The embodiments of the present invention provide another type of WMN fornotifying proxy update, including: a current proxy node of the firstterminal, an intermediate node, and an original proxy node of the firstterminal.

The current proxy node includes:

a first receiving unit, configured to receive an association requestsent by the first terminal;

a first constructing unit, configured to, after association with thefirst terminal is established, construct a proxy update add message inthe way that the address of the proxy information server is taken as thedestination node address, where the proxy update add message takes theaddress of the proxy information server as the address of thedestination node, and includes the address of the current proxy node andthe address of the first terminal; and

a first sending unit, configured to send the proxy update add message tothe destination node according to the address of the destination node inthe first constructing unit, where the proxy update add message is usedfor updating proxy information of the first terminal in the proxyinformation table of the destination node to be the address of thecurrent proxy node, namely the address of the proxy node after the firstterminal switches.

The intermediate node includes:

a third receiving unit, configured to receive the proxy update addmessage sent by the current proxy node, where the proxy update addmessage carries the address of the current proxy node of the firstterminal and the address of the first terminal;

a third searching unit, configured to search, according to the addressof the first terminal carried by the proxy update add message which isreceived by the third receiving unit, the local proxy information tableto acquire the address of the original proxy node of the first terminal,namely the address of the proxy node before the first terminal switches;

a third constructing unit, configured to: construct a proxy update addmessage according to the address of the original proxy node acquired bythe third searching unit, and instruct the third sending unit to sendthe proxy update add message constructed to the destination node, wherethe proxy update add message constructed takes the address of theoriginal proxy node as the destination node address, and includes theaddress of the first terminal and the address of the current proxy node;and

a third sending unit, configured to send the proxy update add message tothe destination node according to the address of the destination node inthe third constructing unit, where the proxy update add message is usedfor updating proxy information of the first terminal in the proxyinformation table of the destination node to be the address of thecurrent proxy node, namely the address of the proxy node after the firstterminal switches.

The original proxy node includes:

a second receiving unit, configured to receive the proxy update addmessage sent by the intermediate node; and

a second proxy table unit, configured to update, according to theaddress of the current proxy node of the first terminal carried by theproxy update add message received by the second receiving unit, proxyinformation of the first terminal in the local proxy information tableto be the address of the current proxy node.

It can be seen from the above technical solution that: By constructing aproxy update add message that includes the address of terminal, theaddress of the current proxy node, and the address of the destinationnode of the terminal, the address of the original proxy node beforeterminal switching is taken as the address of the destination node, andthe proxy update add message constructed is sent to the original proxynode; the proxy update add message is used for updating proxyinformation of the terminal in the proxy information table of theoriginal proxy node to be the address of the current proxy node. In thisway, the original proxy node could be able to update its own proxyinformation table timely, and forward, according to the updated proxyinformation table, packets that take the terminal as destinationterminal. Therefore, it can be ensured that packets received by theoriginal proxy node and sent to the terminal could be received by theterminal. Therefore, with the method for notifying proxy update in theWMN, the WMN node, and the WMN system provided by the embodiments of thepresent invention, packet loss rate during terminal switching could bereduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a WMN for notifying proxy update according to anembodiment of the present invention;

FIG. 2 is a flow chart of a method for notifying proxy update in the WMNaccording to an embodiment of the present invention;

FIG. 3 is a diagram of PU IE format in a proxy update add messageaccording to an embodiment of the present invention;

FIG. 4 is a diagram of a WMN for notifying proxy update according toanother embodiment of the present invention;

FIG. 5 is a flow chart of a method for notifying proxy update in WMNaccording to another embodiment of the present invention;

FIG. 6 is a flow chart of using distribution identifier of a method fornotifying proxy update in the WMN according to another embodiment of thepresent invention;

FIG. 7 is a diagram of a management frame format according to anembodiment of the present invention;

FIG. 8 is a structure diagram of a device for notifying proxy update inWMN according to an embodiment of the present invention; and

FIG. 9 is a structure diagram of a device for notifying proxy update inWMN according to another embodiment of the present invention;

DETAILED DESCRIPTION OF THE EMBODIMENTS

To make the purpose, technical solution and advantage of the presentinvention clearer, a detailed description of the present invention isprovided below with reference to accompanying figures and embodiments

Embodiment 1

As shown in FIG. 1, embodiment 1 of the present invention provides a WMNfor notifying proxy update, including: the original proxy node MAP1before terminal STA1 switches, and the current proxy node MAP2 afterterminal STA1 switches, where MAP1 and MAP2 communicate with each otherthrough the Mesh network, and the path between them has one hop ormulti-hops.

The current proxy node MAP2 of STA1 includes: a receiving unit, asending unit, a resolution unit and a constructing unit.

The receiving unit is configured to receive a request message sent byterminal STA1 or the original proxy node MAP1 of the terminal, where therequest message carries the address of the original proxy node, i.e.,the address of the proxy node before terminal STA1 switches, namely theaddress of MAP1.

The resolution unit is configured to acquire the address of the originalproxy node of terminal STA1, namely the address of MAP1, from therequest message received by the receiving unit.

The constructing unit is configured to construct a proxy update addmessage according to the address of the original proxy node MAP1acquired by the resolution unit, and instruct the sending unit to sendthe proxy update add message constructed to a destination node, wherethe proxy update add message constructed takes the address of theoriginal proxy node MAP1 as the destination node address and the addressof node MAP2 itself as the address of the current proxy node of terminalSTA1, and includes the address of terminal STA1.

The sending unit is configured to send the proxy update add message tothe destination node MAP1 according to the destination node address,namely address of MAP1, where the proxy update add message is used forupdating proxy information of terminal STA1 in the proxy informationtable of the destination node MAP1 to be the address of the currentproxy node, i.e., the address of the proxy node after terminal STA1switches, namely address of MAP2.

The original node MAP1 of STA1 includes: a second receiving unit and asecond proxy table unit.

The second receiving unit is configured to receive the proxy update addmessage sent by the current proxy node MAP2 of terminal STA1, where theproxy update add message carries the address of the current proxy nodeMAP2 of terminal STA1 and the address of terminal STA1.

The second proxy table unit is configured to update proxy information ofterminal STA1 to be the address of the current proxy node MAP2 in thelocal proxy information table of MAP1 itself according to the address ofthe current proxy node of terminal STA1, namely address of MAP2, carriedin the proxy update add message received by the second receiving unit.

In other embodiments, MAP1 could further includes: a second buffer unit,configured to buffer packets sent by nodes or terminals to terminal STA1as destination terminal; a second sending unit, configured to forwardpackets sent by nodes or terminals to terminal STA1 as destinationterminal to terminal STA1 according to updated proxy information ofSTA1. After the receiving unit of MAP2 receives packets forwarded byMAP1 to terminal STA1 as destination terminal, the sending unit of MAP2sends the packets to terminal STA1. For example, before and after STA1switches, STA2 keeps sending packets to STA1 continuously; beforeswitching, STA2 sends packets to MAP1 through MAP4, and then the packetsare forwarded to STA1 by MAP1; after STA1 switches to MAP2, STA2 stillsends packets to STA1 through MAP4. If MAP4 fails to update the localproxy information table timely, it still sends packets that should besent to STA1 to MAP1. At this time, MAP1 does not act as a proxy ofSTA1, and MAP1 buffers packets that are to be sent to STA1 in its ownsecond buffer unit. Then, after MAP1 receives the proxy update addmessage sent by the current proxy node MAP2 of STA1, according to theaddress of MAP2 thereof, MAP1 updates proxy information of terminal STA1in the local proxy information table, and forwards packets that are sentto STA1 from STA2 to MAP2. Further, MAP2 sends the packets to STA1, andthus the packet loss rate is reduced.

In the present embodiment or other embodiments, the address of nodes orterminals could be the Media Access Control (MAC) address of nodes orterminals. During the process of sending the proxy update add messagethrough the Mesh network, nodes receiving the message could update itsown proxy information table according to the message, and update proxyinformation of terminal STA1 to be the address of the current proxy nodeMAP2.

In other embodiments, the WMN for notifying proxy update may furtherinclude a proxy information server, configured to save proxy informationof the Mesh network. The proxy information server could be MPP, such asMP5 in FIG. 1, or other nodes in the configured network, not definedherein. When MAP2 sends the proxy update add message to MAP1, anotherproxy update add message could be constructed and the address of theproxy information server may be taken as the destination node address.Then, the proxy update add message is sent to the proxy informationserver. Therefore, after the proxy information server receives themessage, MAP2 could update its own proxy information table according tothe proxy update add message.

Embodiment 2

As shown in FIG. 2, embodiment 2 of the present invention provides amethod for notifying proxy update in a WMN. For clear description, MAP1is taken as the original proxy node, namely the proxy node before STA1switches; MAP2 is taken as the current proxy node, namely the proxy nodeafter STA1 switches; and STA1 switches from MAP1 to MAP2. The method fornotifying proxy update in the WMN includes the following steps:

Step 101: Acquire the address of the original proxy node, namely theaddress of the proxy node before the terminal switches.

In this step, the acquiring of the address of the original proxy node,namely the address of the proxy node before the terminal switches, couldbe that:

MAP2 receives a re-association request sent by terminal STA1, where there-association request carries the original proxy node address ofterminal STA1, namely address of MAP1, and acquires the address of theoriginal proxy node MAP1 of terminal STA1 from the re-associationrequest; or

terminal STA1 initiates a rapid authentication request message duringrapidly switching, at this time, MAP1 acts as the proxy of STA1 wherethe authentication request message is forwarded to the destination nodeMAP2 through the proxy node MAP1, and the message needs to carry its ownMAC address when the MAP1 forwards the message; or

MAP2 receives other messages that carry the address of MAP1 to acquirethe address of MAP.

Step 102: Construct the proxy update add message, where the proxy updateadd message includes: the address of the terminal, the address of thecurrent proxy node after the terminal switches, and the address of thedestination node after the terminal switches.

In this step, in the proxy update add message constructed by MAP2, theacquired address of the original proxy node, i.e., the address of theproxy node before the terminal switches, namely address of MAP1, istaken as the destination node address, the address of MAP2 itself istaken as the address of the current proxy node, namely the address ofthe proxy node after the terminal switches, and the address of theterminal is also carried in the proxy update add message constructed.There are several ways for acquiring the address of the terminal, whichwill not be defined specifically herein, for example, acquiring theaddress of STA1 from the re-association request sent by terminal STA1;or acquiring the address of STA1 from the probe request sent by terminalSTA1; or acquiring the address of STA1 by interacting with terminal STA1in other ways.

Step 103: Take the original proxy node address as destination nodeaddress, send the proxy update add message to the original proxy node,where the proxy update add message is used for updating proxyinformation of the terminal in proxy information table of the originalproxy node to be the current proxy node address.

In this step, MAP2 sends the proxy update add message constructed toMAP1, and instructs MAP1 to update proxy information of terminal STA1 tothe address of MAP2 in its own proxy information table. Furthermore,MAP2 could construct another proxy update add message which takes theproxy information server address as destination node address, carry theaddress of terminal STA1 and the address of the current proxy node MAP2,namely the address of proxy node MAP2 after terminal STA1 switches, inthe proxy update add message, send the proxy update add message to theproxy information server, and instruct the proxy information server toupdate proxy information of terminal STA1 in its own proxy informationtable to the address of the current proxy node MAP2 of the terminal. Itis understandable that the address of the proxy information server couldbe known by MAP2 through configuration or other ways. In the presentembodiment, the proxy information server is assumed as the Mesh networknode MP5. When the proxy update add message is being constructed, theformat of the proxy update add message defined in IEEE 802.11s StandardDraft can be adopted, where the Proxy Update IE is carried, aDestination Address (destination node address) field is added to theProxy Update IE, and the destination node address of the proxy updateadd message can be filled in. The format of the Proxy Update IE carriedin the proxy update add message constructed in the present embodiment isshown in FIG. 3. Table 1 shows the description of each field.

TABLE 1 Description of each field in PU IE Parameter Description IDProxy Update element ID, which distinguishes one Proxy Update elementfrom other IEs Length Length of the IE, ranging from Flags field to thelast field Flags 0: the add proxy information; 1: proxy delete proxyinformation; Bit17: reserved Sequence Number Serial number of PU IE,indicating “new” or “old” and maintained by each node respectively ProxyAddress MAC address of proxy node of the terminal, namely MAC address ofthe source node of the PU message Destination Address MAC address of thedestination node of the proxy update message Number of Proxied Thenumber of terminals Address (N) Proxied MAC Address #I MAC address ofterminal I

After MAP2 constructs a proxy update add message with the address ofMAP1 as destination node address and a proxy update add message with theaddress of MP5 as destination node address, it sends the proxy updateadd messages to MAP1 and MP5 respectively through the Mesh network. Inthe proxy update add message sent to MAP1, the MAP1 as destination nodeaddress is carried in “Destination Address” field, address of thecurrent proxy node MAP2 of STA1 is carried in “Proxy Address” field, andaddress of terminal STA1 is carried in “Proxied MAC Address #I (MACaddress of terminal I) field. In a proxy update add message, several“Proxied MAC Address #I” fields can be set, and therefore if multipleterminals switch from MAP1 to MAP2, MAP2 can send a proxy update addmessage to MAP1 for each STA, or carry addresses of all terminalsswitching from MAP1 to MAP2 within a period of time in the proxy updateadd message and send them to MAP1.

Step 104: Receive packets which take the terminal as destinationterminal forwarded by the original proxy node, and forward the packetsto the terminal.

In the step, after the original proxy node MAP1 of STA1 receives theproxy update add message sent by MAP2 through the Mesh network, MAP1acquires the address of the current proxy node MAP2 of STA1 from theproxy update add message, updates its own local proxy information table,and sends packets, which are buffered by MAP1 itself and take STA1 asdestination terminal, to MAP2 through the Mesh network. For example,before and after terminal STA1 switches from MAP1 to MAP2, terminal STA2always sends packets which take STA1 as destination terminal to STA1through MAP4; after STA1 switches to MAP2, if MAP4 fails to update itsown local proxy information table timely, it still sends packets to MAP1which should be sent to STA1; at this time MAP1 does not act as proxy ofSTA1 any more, and MAP1 buffers packets sent to STA1 in its own bufferunit; when MAP1 receives the proxy update add message sent by thecurrent proxy node MAP2 of STA1, it forwards packets to MAP2 whichshould be sent to STA1 from STA2 according to the address of MAP2thereof; after MAP2 receives packets which are forwarded by MAP1 andtake terminal STA1 as destination terminal, it further sends the packetsto STA1, and therefore it is ensured that before and after STA1switches, all the packets sent to STA1 could be forwarded to STA1correctly, and packet loss rate could be reduced.

In other embodiments, in step 101, after MAP2 acquires the address ofthe original proxy node MAP1 of terminal STA1, MAP2 further updatesproxy information of terminal STA1 to the address of the current proxynode MAP2 of STA1 in its own local proxy information table. There aretwo situations for updating proxy information of terminal STA1 in thelocal proxy information table:

The first situation: The local proxy information table of MAP2 does nothave proxy information of terminal STA1. At this time, MAP2 updatesproxy information of terminal STA1 in the local proxy information tablein the way of adding the address of the current proxy node of terminalSTA1 as the address of MAP2 in the local proxy information table.

The second situation: In the local proxy information table of MAP2, theproxy node address of terminal STA1 is not the address of the currentproxy node MAP2 of STA1. For example, in the local proxy informationtable of MAP2, the original proxy node address of terminal STA1 is theaddress of MAP1. At this time, MAP2 updates proxy information ofterminal STA1 in the local proxy information table in the way ofmodifying the proxy information of STA1 from the address of MAP1 to theaddress of MAP2 in its own local proxy information table.

In the present embodiment, nodes in the path from MAP2 to MAP1 and nodeMAP1 update their own local proxy information table after receiving theproxy update add message constructed by MAP2 mentioned above; nodes inthe path from MAP2 to MP5 and node MP5 update their own local proxyinformation table after receiving the proxy update add messageconstructed by MAP2.

In the present embodiment, by carrying the address of the destinationnode in the proxy update add message, the current proxy node of theterminal is able to send the proxy update add message to the originalproxy node of the terminal timely. Therefore, the original proxy nodecould acquire the address of the current proxy node of the terminaltimely, and forward packets that take the terminal as destinationterminal buffered in the original proxy node to the terminal through theaddress of the current proxy node.

In other embodiment, as shown in FIG. 1, in a WMN provided by theembodiments of the present invention, the following scenario occurs:Terminal STA1 first switches or accesses to MAP1 from other MAP; then,terminal STA1 switches from MAP1 to the current proxy node MAP2 rapidly.After STA1 associates with MAP1, MAP1 sends the proxy update add messageto proxy information server, and after STA1 rapidly switches to MAP2 andassociates with MAP2, MAP2 sends the proxy update add message to theproxy information server. Because of uneven distribution of the networkair interface environment, the proxy update add message sent by MAP2will reach the proxy information server prior to the proxy update addmessage sent by MAP1. Therefore, the proxy information server firstupdates proxy information of STA1 to the address of MAP2, and thenupdates proxy information of STA1 to the address of MAP1, so that theproxy information server saves error proxy information of terminal STA1,that is, the proxy information of STA1 finally saved in the proxy serveris the address of MAP1. However, through the technical solution of thepresent embodiment, because MAP2 sends the proxy update add message toMAP1, the proxy information of the terminal saved in MAP1 is correct,namely address of MAP2. Thus, even if the gateway node or other nodes inthe network send packets that should be sent to terminal STA1 to MAP1incorrectly, MAP1 could still forward the packets to the current proxynode MAP2 of terminal STA1 correctly by querying proxy information ofterminal STA1 in the local proxy information table.

Embodiment 3

As shown in FIG. 4, embodiment 3 of the present invention provides a WMNfor notifying proxy update, including: original proxy node MAP1 beforeterminal STA1 switches, current proxy node MAP2 after terminal STA1switches, and intermediate node MP3 in the path from MAP2 to proxyserver MP5. The intermediate node could be any nodes except MAP1 andMAP2 in the Mesh network which have or can acquire the proxy informationtable, such as MP3 in FIG. 4. MP3 herein could be a MAP or common Meshnode which has or can acquire the proxy information table, where MP3,MAP1, MAP2 and MP5 communicate with each other through the Mesh network,and paths between nodes could have one hop or multi-hops.

The current proxy node MAP2 of STA1 includes: a receiving unit, asending unit, and a constructing unit.

The receiving unit is configured to receive an association request sentby the receiving terminal STA1.

The constructing unit is configured to: after MAP2 establishesassociation with terminal STA1 according to the association request,construct the proxy update add message in the way that the address ofthe proxy information server MP5 is taken as the destination nodeaddress, and instruct the sending unit to send the proxy update addmessage constructed to the destination node, where the proxy update addmessage constructed takes the address of the proxy information serverMP5 as destination node address and the address of node MAP2 itself asthe current proxy node address of terminal STA1, and includes theaddress of terminal STA1.

The sending unit is configured to send the proxy update add message tothe destination node MP5 through the Mesh network according to thedestination node address, namely address of MP5, where the proxy updateadd message is used for updating proxy information of terminal STA1 inthe proxy information table of the destination node MP5 to be theaddress of the current proxy node, i.e., the address of the proxy nodeafter terminal STA1 switches, namely address of MAP2.

The original proxy node MAP1 of STA1 includes: a second receiving unitand a second proxy table unit.

The second receiving unit is configured to receive the proxy update addmessage sent by the intermediate node MP3, where the proxy update addmessage carries the address of the current proxy node MAP2 of terminalSTA1 and the address of terminal STA1.

The second proxy table unit is configured to acquire the current proxynode address of terminal STA1, namely address of MAP2, from the proxyupdate add message received by the second receiving unit, and updateproxy information of terminal STA1 in the local proxy information tableof MAP1 itself to the address of the current proxy node MAP2.

In other embodiments, MAP1 may also include: a second buffer unit,configured to buffer packets sent by nodes or terminals to terminal STA1as destination terminal; and a second sending unit, configured toforward packets sent by nodes or terminals to terminal STA1 asdestination terminal to terminal STA1 according to updated proxyinformation of STA1. After the receiving unit of MAP2 receives packetsforwarded by MAP1 to terminal STA1 as destination terminal, the sendingunit of MAP2 sends the packets to terminal STA1.

The intermediate node MP3 includes: a third receiving unit, a thirdsending unit, a third searching unit, and a third constructing unit.

The third receiving unit is configured to receive the proxy update addmessage sent by the current proxy node MAP2, namely the proxy node afterterminal STA1 switches, where the proxy update add message includes theaddress of terminal STA1 and the current proxy node address of terminalSTA1, namely address of MAP2.

The third searching unit is configured to search the local proxyinformation table to acquire the address of the original proxy node MAP1of terminal STA1 according to the address of terminal STA1 carried bythe proxy update add message which is received by the third receivingunit.

The constructing unit is configured to construct the proxy update addmessage according to the address of the original proxy node MAP1acquired by the third searching unit, and instruct the third sendingunit to send the proxy update add message constructed to the destinationnode, where the proxy update add message constructed takes the addressof the original proxy node MAP1 of terminal STA1 as destination nodeaddress, and includes the address of terminal STA1 and the address ofthe current proxy node MAP2 of terminal STA1.

The sending unit is configured to send the proxy update add message tothe destination node MAP1 according to the destination node address,namely address of MAP1, where the proxy update add message is used forupdating proxy information of terminal STA1 in the proxy informationtable of the destination node MAP1 to be the address of the currentproxy node MAP2.

In other embodiments, the WMN for notifying proxy update furtherincludes a proxy information server, configured to save proxyinformation of the Mesh network, and the proxy information server couldbe an MMP, such as MP5 in FIG. 4 or other nodes in the configurednetwork that are not defined herein. When MP3 sends the proxy update addmessage to MAP1, the received proxy update add message sent by MAP2could still be sent to the proxy information server MP5 so that it couldupdate its own proxy information table according to the proxy update addmessage after the proxy information server receives the message.

Embodiment 4

As shown in FIG. 5, embodiment 4 of the present invention provides amethod for notifying proxy update in a WMN. For clear description, MAP1is taken as the original proxy node, namely the proxy node before STA1switches; MAP2 is taken as the current proxy node, namely the proxy nodeafter STA1 switches; and the Mesh node MP3 is taken as a node in thepath from MAP2 to proxy information server MP5 in network. The methodfor notifying proxy update in the WMN includes:

Step 200: Receive the proxy update add message. The proxy update addmessage includes: destination node address, current proxy node addressof the terminal, and terminal address.

In this step, MP3 receives the proxy update add message which is sent bythe current proxy node MAP2 of terminal STA1 through the Mesh network.

Step 201: Acquire the address of the original proxy node, namely theaddress of the proxy node before the terminal switches.

In this step, the acquiring of the address of the original proxy node,namely the address of the proxy node before the terminal switches is:After MP3 receives the proxy update add message sent by the currentproxy node MAP2 of terminal STA1, according to the address of terminalSTA1 carried in the proxy update add message, MP3 searches its own localproxy information table, acquires the address of the original proxy nodeMAP1 of terminal STA1. The format of the proxy update add messagedefined in IEEE 802.11s Standard Draft can be adopted, where a ProxyUpdate IE is carried, a Destination Address (destination node address)field is added to the Proxy Update IE, and the destination node addressof the proxy update add message is filled in. The format of the ProxyUpdate IE carried in the proxy update add message sent by MAP2 is shownin FIG. 3, and description of each field is shown in Table 1. MAP2 takesthe address of the proxy information server MP5 as destination nodeaddress in the proxy update add message sent by MAP2 and sends the proxyupdate add message to MP5 through the Mesh network, and MP3 is in thepath from MAP2 to MP5. Therefore, MAP2 could receive the proxy updateadd message.

Step 202: Construct a new proxy update add message, where the proxyupdate add message includes: address of the terminal, current proxy nodeaddress after the terminal switches, and destination node address.

In this step, the constructing of the new proxy update add message byMP3 could be: copying the received proxy update add message sent byMAP2, and modifying the destination node address of the proxy update addmessage copied to the address of the original proxy node MAP1. The proxyupdate add message constructed by MP3 takes the address of originalproxy node MAP1 as the destination node address, and includes theaddress of terminal STA1 carried in the proxy update add message sent bythe current proxy node MAP3 and the address of the current proxy nodeMAP2, namely the address of proxy node MAP2 after terminal STA1switches.

Step 203: Take the original proxy node address as destination nodeaddress, send the proxy update add message to the original proxy node,where the proxy update add message is used for updating proxyinformation of the terminal in proxy information table of the originalproxy node to be the current proxy node address.

The proxy update add message is sent to the proxy information server byusing the proxy information server address as destination node address.

In this step, MP3 takes the address of the original proxy node MAP1 ofSTA1 as destination node address, sends the proxy update add messageconstructed to MAP1, instructs MAP1 to update proxy information ofterminal STA1 to the address of MAP2 in proxy information table of MAP1itself according to the proxy update add message. Furthermore, MP3 couldforward the received proxy update add message sent by MAP2 to proxyinformation server MP5. For example, if the original proxy update addmessage sent by MAP2 takes the address of MP5 as destination nodeaddress, the original proxy update add message sent by MAP2 could beforwarded to MP5 through the Mesh network directly. It is understandablethat the address of the proxy information server could be known by MP3through configuration or other ways. When the proxy update add messageis being constructed, the format of the proxy update add message definedin IEEE 802.11s Standard Draft can be adopted, where the Proxy Update IEis carried, a Destination Address (destination node address) field isadded to the Proxy Update IE, and the destination node address of theproxy update add message is filled in. The format of the Proxy Update IEcarried by the proxy update add message constructed in the presentembodiment is shown in FIG. 3, and description of each field is shown inTable 1.

After constructing the proxy update add message with the address of MAP1as destination node address, MP3 sends the proxy update add message toMAP1 and MP5 through the Mesh network. In the proxy update add messagesent to MAP1, the destination node address as MAP1 is carried in“Destination Address” field, address of the current proxy node MAP2 ofSTA1 is carried in “Proxy Address” field, and address of terminal STA1is carried in “Proxied MAC Address #I” field.

Step 204: Receive packets that take the terminal as destination terminaland are forwarded by the original proxy node, and forward the packets tothe terminal.

In the step, after the original proxy node MAP1 of STA1 receives theproxy update add message sent by MP3 through the Mesh network, MAP1acquires the address of the current proxy node MAP2 of STA1 from theproxy update add message, updates its own local proxy information table,and sends packets, which are buffered by MAP1 itself and take STA1 asdestination terminal, to MAP2 through the Mesh network. For example,before and after terminal STA1 switches from MAP1 to MAP2, terminal STA2always sends packets that take STA1 as destination terminal to STA1through MAP4; after STA1 switches to MAP2, if MAP4 fails to update itsown local proxy information table timely, it still sends packets to MAP1that should be sent to STA1; at this time, MAP1 does not act as theproxy of STA1 any more, and MAP1 buffers packets sent to STA1 in its ownbuffer unit; when MAP1 receives the proxy update add message sent bynode MP3, it forwards packets to MAP2 that should be sent to STA1 fromSTA2 according to the address of MAP2 thereof; after MAP2 receivespackets forwarded by MAP1 that take terminal STA1 as destinationterminal, it further sends the packets to STA1. Therefore, it is ensuredthat before and after STA1 switches, all the packets sent to STA1 couldbe forwarded to STA1 correctly, and packet loss rate could be reduced.

In other embodiments, in step 201, after MP3 acquires the address of theoriginal proxy node MAP1 of terminal STA1, MP3 further updates proxyinformation of terminal STA1 to the address of the current proxy nodeMAP2 of STA1 in its own local proxy information table. For example, inits own local proxy information table, MP3 modifies proxy information ofSTA1 from the address of MAP1 to the address of MAP2. Thereof, there aretwo situations for updating proxy information of terminal STA1 in thelocal proxy information table: The local proxy information table of MP3does not have proxy information of STA1; or, in the local proxyinformation table of MP3, the proxy information of STA1 is the addressof the original proxy node MAP1. Detailed update process for bothsituations can refer to description of Embodiment 2, which is notrepeated herein.

In other embodiments, the proxy update add message may further includedistribution identifier. The distribution identifier is used foridentifying whether the proxy update add message is sent to the originalproxy node or not. For example, reserved bits in Flags field are used asthe distribution identifier. Take Bit 1 as example. When Bit 1 is 1, itmeans that the proxy update add message has been forwarded to theoriginal proxy node of the terminal; when Bit 1 is 0, it means that theproxy update add message has not been forwarded to the original proxynode of the terminal. If address information of multiple terminals iscarried by a proxy update add message, different distributionidentifiers can be set separately for different terminal addresses, forexample, using seven bits (Bit 2-Bit 7) reserved in Flags fields torepresent distribution situations of seven different terminal addresses.Further, an STA flags (terminal identifier) field could be added, thelength of which is multiple of 8 bits. Therefore, the largest number ofaddress information of the terminal carried in the proxy update addmessage is equal to the length of STA flags. In addition, flags fieldcan be added for each terminal address to identify whether a node hasforwarded the proxy update add message of the terminal to the originalproxy node or not. The current proxy node could set the distributionidentifier bits corresponding to terminal addresses that need not bedistributed to the status that the proxy update add message has beensent to the original proxy node. Then, the intermediate node will notdistribute for address information of the terminals, where distributionherein means that the proxy update add message is sent to the originalproxy node of the terminal and the proxy information server according tothe proxy update add message sent by the current proxy node of theterminal. FIG. 6 shows the steps of using the distribution identifier:

Step 301: The current proxy node MAP2 of STA1 constructs a proxy updateadd message. In the proxy update add message, the address of STA1 iscarried in “Proxied MAC Address #I (MAC address of the terminal I)field, and the address of proxy information server MP5 is taken asdestination node address in “Destination Address” field, and “ProxyAddress” field carries the address of the current proxy node MAP2 ofSTA1. MAP2 sets the distribution identifier bit corresponding to STA1 inthe proxy update add message constructed to the status of not sendingthe proxy update add message to the original proxy node, that is, theproxy update add message is not sent to the original proxy node MAP1 ofSTA1. Of course, in the proxy update add message constructed, multipleterminal addresses could be carried in the way mentioned above. If it isunnecessary to distribute for some terminal addresses thereof, MAP2 setsthe distribution identifier bits corresponding to these terminals to thestatus of having sent the proxy update add message to original proxynode.

Step 302: MAP2 sends the proxy update add message constructed to MP5through the Mesh network.

Step 303: The intermediate node MP3 receives the proxy update addmessage sent by the current proxy node MAP2 of STA1.

Step 304: MP3 determines whether to perform distribution or notaccording to the distribution identifier in the proxy update add messagereceived. For example, MP3 determines whether to send the proxy updateadd message to the current proxy node MAP1 or not according to thedistribution identifier bit corresponding to STA1 in the proxy updateadd message; if the proxy update add message has been sent to originalproxy node MAP1, the process proceeds to step 305; otherwise, theprocess proceeds to step 306.

Step 305: Forward the proxy update add message to the next hop. When theproxy update add message has been sent to the original proxy node MAP1,the proxy update add message is forwarded to next hop, and proxyinformation of terminal STA1 in the local proxy information of MP3itself is updated according to the proxy update add message.

Step 306: Construct a new proxy update add message, modify thedistribution identifier to the status of having sent the proxy updateadd message to the original proxy node, and send the proxy update addmessage constructed to the original proxy node and the proxy informationserver. For example, if the proxy update add message is not sent tooriginal proxy node MAP1, the process proceeds to step 202, and in thestep 202, the distribution identifier corresponding to STA1 is modifiedto the status of having sent the proxy update add message to theoriginal proxy node; then, the proxy update add message carrying thedistribution identifier of having sent the proxy update add message toMAP1 is sent to MAP1 and MP5 based on that the addresses of originalproxy node MAP1 and proxy information server MP5 serve as thedestination node address.

In other embodiments, if all intermediate nodes in the path from MAP2 toMP5 could not distribute the proxy update add message to MAP1, the proxyupdate add message could be distributed to MAP1 by MP5. For example,after MP5 receives the proxy update add message sent by MAP2 through theMesh network, it copies the proxy update add message, and modifies thedestination node address of the copied proxy update add message to theaddress of MAP1, and forwards the proxy update add message that takesMAP1 as destination node address to MAP1 through the Mesh network; orafter receiving the proxy update add message sent by MAP2 through theMesh network, MP5 updates its own local proxy information table,modifies the destination node address of the message to the address ofMAP1 directly, and forwards the proxy update add message that takes MAP1as destination node address to MAP1 through the Mesh network. If theproxy update add message contains a distribution identifier, MP5 couldmake judgment according to the distribution identifier that it onlyneeds to update its own local proxy information table when the proxyupdate add message has been sent to MAP1 and it updates its own localproxy information table and sends the proxy update add message to MAP1based on that MAP1 serves as the destination node address when the proxyupdate add message has not been sent to MAP1. Reasons for not being ableto forward messages to MAP1 may be: Routing tables of nodes in the pathhave no path to MAP1; or, routing tables of nodes in the path do nothave proxy information of the terminal, and MP5 could communicate withMAP1 as the proxy information server, and therefore could ensure successof distribution.

In the present embodiment, nodes in the path from MAP2 to MP3 and nodeMP3 update their own local proxy information table after receiving theproxy update add message mentioned above constructed by MAP2; nodes inthe path from MP3 to MP5, node MP5, nodes in the path from MP3 to MAP1,and node MAP1 update their own local proxy information table afterreceiving the proxy update add message constructed by MAP2.

In the present embodiment, by carrying the address of the destinationnode in the proxy update add message, the current proxy node of theterminal is able to send the proxy update add message to the originalproxy node of the terminal timely. Therefore, the original proxy nodecould acquire the address of the current proxy node of the terminaltimely, and forward packets which take the terminal as destinationterminal buffered in the original proxy node to the terminal through theaddress of the current proxy node.

Embodiment 5

Embodiment 5 provides another method for carrying destination nodeaddress in the proxy update add message, as shown in FIG. 7. Address 3(Addr3) field in the management frame of IEEE 802.11 standard is reusedfor carrying the destination node address. Addr 3 field in themanagement frame MAC head is re-adopted, assigned with a new meaning,and used to represent MAC address of the destination node of the proxyupdate add message. Addr 3 field of MAC head is Basic Service SetIdentification (BSSID) field.

In the above embodiment, the node address field in the proxy update addmessage could be deleted, and the method of Addr 3 field in the reusedMAC head provided by the present embodiment could be used for carryingthe destination node address.

After proxy update using above embodiments, during data packetforwarding, Addr 3 field of the data packet is used for carrying thedestination node MAC address. After the forwarding node acquires thedata packet, its own local proxy information table is searched firstlyaccording to address 5 (destination terminal MAC address) of the datapacket. If the local proxy information table of forwarding node itselfhas proxy information of the destination terminal, the MAC address ofthe current proxy node of the destination terminal is acquired and thedata packet is forwarded to the current proxy node of the destinationterminal directly according to the address of the current proxy node. Ifthe local proxy information table of the forwarding node itself has noproxy information of the destination terminal, forwarding is performedaccording to address 3 (Mesh destination node address) of the datapacket. As the method of notifying proxy update in above embodiments isadopted, the forwarding node could update its own local proxyinformation table timely. Further, in the process of data forwardingmentioned above, data packets are sent to the correct proxy node of thedestination terminal by searching the local proxy information table toacquire the correct current proxy node of the destination terminal.Therefore, data forwarding burden of other nodes in the network could bereduced, and time delay and packet loss rate could be reduced duringterminal switching.

Embodiment 6

As shown in FIG. 8, embodiment 6 provides a device for notifying proxyupdate in WMN, the device includes:

a receiving unit 801, configured to receive a request message sent bythe receiving terminal or the original proxy node, namely the proxy nodebefore terminal switching, where the request message carries the addressof the original proxy node, namely the address of the proxy node beforeterminal switching;

a sending unit 802, configured to send the proxy update add message tothe destination node according to the destination node address, wherethe proxy update add message is used for updating proxy information ofthe terminal in the proxy information table of the destination node tobe the address of the current proxy node, namely the address of theproxy node after the terminal switches;

a resolution unit 803, configured to acquire the address of the originalproxy node of the terminal from the request message received by thereceiving unit 801; and

a constructing unit 804, configured to: construct the proxy update addmessage according to the address of the original proxy node acquired bythe resolution unit 803, and instruct the sending unit 802 to send theproxy update add message constructed to destination node, where theproxy update add message constructed takes the address of the originalproxy node as destination node address, and includes the address of thecurrent proxy node and the address of the terminal.

In other embodiments, the device for notifying proxy update alsoincludes proxy table unit 805, configured to: save the local proxyinformation table, and update the local proxy information tableaccording to the request message received by the receiving unit 801.

Further, the device for notifying proxy update in the present embodimentcould be set in the MAP, which can be current proxy node MAP2 ofterminal STA1 in the WMN provided in embodiment 1.

Embodiment 7

As shown in FIG. 9, embodiment 7 provides another device for notifyingproxy update in the WMN, the device includes:

a receiving unit 901, configured to receive the proxy update add messagesent by the current proxy node, namely the proxy node after terminalswitching, where the proxy update add message carries the address of thecurrent proxy node of the terminal and the address of the terminal;

a sending unit 902, configured to send the proxy update add message tothe destination node according to the destination node address, wherethe proxy update add message is used for updating proxy information ofthe terminal in the proxy information table of the destination node tobe the address of the current proxy node;

a searching unit 903, configured to search, according to the address ofthe terminal carried in the proxy update add message received by thereceiving unit 901, the local proxy information table to acquire theaddress of the original proxy node, namely the address of the proxy nodebefore the terminal switches; and

a constructing unit 904, configured to construct the proxy update addmessage according to the address of the original proxy node of theterminal acquired by the searching unit 903, and instruct the sendingunit 902 to send the proxy update add message constructed to thedestination node, where the proxy update add message constructed takesthe address of the original proxy node as destination node address, andincludes the address of the terminal and the address of the currentproxy node.

In other embodiments, the device for notifying proxy update alsoincludes: identifier determination unit 905, configured to make judgmentaccording to the distribution identifier carried in the proxy update addmessage received by the receiving unit 901, where the distributionidentifier is used for identifying whether the proxy update add messageis sent to the original proxy node or not; when the proxy update addmessage has been sent to the original proxy node, the identifierdetermination unit instructs the sending unit 902 to forward the proxyupdate add message to next hop; when the proxy update add message hasnot been sent to the original proxy node, the identifier determinationunit instructs the searching unit 903 to search the local proxyinformation table and acquire the address of the original proxy node,namely the address of the proxy node before terminal switching, and/orinstructs the constructing unit 904 to construct a proxy update addmessage according to original proxy node address of terminal acquired bythe searching unit 903, and sets the distribution identifier in theproxy update add message constructed to the status of having sent proxyupdate add message to original proxy node. The constructing unit 904 isalso used for constructing a proxy update add message according tonotification of the identifier determination unit, and settingdistribution identifier in the proxy update add message constructed tothe status of having sent proxy update add message to original proxynode. Setting of distribution identifier could be completed by themodifying unit 9042.

In other embodiments, the device for notifying proxy update alsoincludes: a proxy table unit 906, configured to save the local proxyinformation table, and update the local proxy information tableaccording to the proxy update add message received by the receiving unit901, or provide an interface for the searching unit 903 to search theproxy information table. Searching of the proxy information table by thesearching unit 903 may be as follows: The searching unit 903 reads theproxy information table, index for the proxy information table accordingto the terminal address, and acquires proxy information corresponding tothe terminal address.

In other embodiments, the device for notifying proxy update may includeboth the identifier determination unit 905 and proxy table unit 906mentioned above.

The device for notifying proxy update in the present embodiment may beset in the MP, which could be the intermediate node MP3 in the WMNprovided by embodiment 3.

Embodiment 8

The embodiment of the present invention provides another method fornotifying proxy update in the WMN. The difference between the method ofthe present embodiment and method provided in embodiment 4 is asfollows:

After receiving the proxy update add message, the node firstly judgeswhether proxy information of terminal STA1 in the proxy update addmessage is carried in its own local proxy information table; if not, thelocal proxy information table is updated directly by adding proxyinformation of terminal STA1 in the local proxy information table whichis the address of MAP2; if proxy information of terminal STA1 is carriedin the local proxy information table of node itself, a judgment isfurther made about whether proxy information which already exists in thelocal proxy information table of node itself is consistent with theaddress of the current proxy node MAP2 of terminal STA1 in the proxyupdate add message or not; if they are consistent, the received proxyupdate add message is forwarded to next hop or the received proxy updateadd message is discarded; if they are inconsistent, the proxyinformation in the local proxy information table of terminal STA1,namely, address of original proxy node MAP1 of terminal STA1, isacquired, and a new proxy update add message is constructed according toMAP1, and update the local proxy information table and send the newproxy update add message constructed to MAP1 after constructing the newproxy update add message based on that MAP1 serves as destination nodeaddress.

Furthermore, in embodiments mentioned above, nodes that receive theproxy update add message judge, before forwarding the message, whetherthe nodes themselves are destination nodes or not: if nodes that receivethe proxy update add message are destination nodes, the nodes do notforward the proxy update add message; otherwise, the message isforwarded; or, after receiving the proxy update add message, the nodemakes a judgment about whether the node it self is the destination nodeor not: if the node itself is not the destination node, the proceedingprocess is followed; if the node itself is the destination node, thelocal proxy information table is updated directly and it is unnecessaryto forward or construct the new proxy update add message.

In conclusion, above embodiments are some exemplary embodiments of thepresent invention but not intended to limit the present invention. Anymodification, equivalent replacement, improvement within the spirit andprinciple of the present invention should be regard as being included inthe protection scope of the present invention.

1. A method for notifying proxy update in a Wireless Mesh Network (WMN), comprising: constructing a proxy update add message, wherein the proxy update add message comprises an address of a terminal, an address of a current proxy node after terminal switching, and a destination node address, wherein the destination node address is an address of an original proxy node, which is the proxy node before terminal switching; sending the proxy update add message to the original proxy node, wherein the proxy update add message is for updating proxy information of the terminal in a proxy information table of the original proxy node to be the address of the current proxy node; receiving the proxy update add message sent by the current proxy node, and searching a local proxy information table for acquiring the address of the original proxy node of the terminal according to the address of the terminal carried in the proxy update add message; wherein the proxy update add message sent by the current proxy node further comprises a distribution identifier configured to identify whether the proxy update add message is sent to the original proxy node or not; and after receiving the proxy update add message sent by the current proxy node, according to the distribution identifier, the proxy update add message is forwarded to a next hop when the proxy update add message has been sent to the original proxy node; and when the proxy update add message has not been sent to the original proxy node, the proxy update add message is constructed and the distribution identifier is modified to identify that the proxy update add message has been sent to the original proxy node.
 2. The method according to claim 1, wherein the constructing of the proxy update add message is: according to the proxy update add message sent by the current proxy node, constructing a new proxy update add message, wherein the new proxy update add message takes the original proxy node address as the destination node address, and comprises the address of the terminal carried in the proxy update add message sent by the current proxy node and the address of the current proxy node, which is the proxy node after terminal switching.
 3. The method according to claim 1, wherein the acquiring of the address of the original proxy node, comprises: receiving a request message sent by the terminal or the original proxy node, wherein the request message carries the address of the original proxy node of the terminal; and acquiring the address of the original proxy node of the terminal from the request message.
 4. The method according to claim 3, wherein constructing a proxy update add message comprises: according to the address of the original proxy node, constructing a new proxy update add message, wherein the new proxy update add message takes the address of the original proxy node as the destination node address, and comprises the address of the current proxy node, which is the proxy node after the terminal switching, and the address of the terminal.
 5. The method according to 1, wherein: after the step of acquiring the address of the original proxy node, the method further comprises: updating the proxy information of the terminal to be the address of the current proxy node in the local proxy information table.
 6. The method according to claim 1, wherein the proxy update add message carries the destination node address by: increasing a destination node address field in a proxy update information element (Proxy Update IE) for carrying the destination node address; or reusing a Basic Service Set Identification (BSSID) field of a media access control (MAC) head for carrying the destination node address.
 7. A Wireless Mesh Network (WMN) node for notifying proxy update in a WMN, comprising: a constructing unit configured to construct a proxy update add message, wherein the proxy update add message takes a address of an original proxy node of a terminal as a destination node address, and includes an address of the terminal and an address of a current proxy node of the terminal; a sending unit configured to send the proxy update add message to a destination node according to the destination node address acquired by the constructing unit, wherein the proxy update add message is configured for updating proxy information of the terminal in a proxy information table of the destination node to be the address of the current proxy node of the terminal; a receiving unit configured to receive the proxy update add message sent by the current proxy node, which is the proxy node after terminal switching, wherein the proxy update add message comprises the address of the terminal and the address of the current proxy node of the terminal; a searching unit configured to search a local proxy information table to acquire, according to the address of the terminal carried in the proxy update add message received by the receiving unit, the address of the original proxy node, which is the proxy node before terminal switching; and an identifier judging unit configured to judge a distribution identifier carried in the proxy update add message received by the receiving unit, wherein the distribution identifier is configured to identify whether the proxy update add message has been sent to the original proxy node or not, and the constructing unit is further configured to construct the proxy update add message when a judging result of the identifier judging unit is that the proxy update add message has not been sent to the original proxy node, and modify the distribution identifier in the proxy update add message to identify that the proxy update add message has been sent to the original proxy node.
 8. The WMN node according to claim 7, wherein the constructing unit comprises: a copying unit configured to copy the proxy update add message received by the receiving unit; and a modifying unit configured to set the destination node address of the proxy update add message copied by the copying unit to the address of the original proxy node address acquired by the searching unit.
 9. The WMN node according to claim 7, wherein the WMN node further comprises: a receiving unit configured to receive a request message sent by the terminal or the original proxy node, which is the proxy node before terminal switching, wherein the request message carries the address of the original proxy node, which is the address of the proxy node before terminal switching; and a resolution unit configured to acquire the address of the original proxy node address of the terminal from the request message received by the receiving unit.
 10. The WMN node according to any one of claims 7, wherein the WMN node further comprises: a proxy table unit configured to save the local proxy information table, and update the local proxy information table according to the message received by the receiving unit. 